Removing the bumper is OK
It's as per your OP
Lights out, screws off.
Screws out of the mudguard, not forgetting the one that is behind the mud shield at the top each side - you have to bend the shield away to get to them.

What NOT to do is be tempted to pull the bumper side parts away from the car.
As you have said, just pull the bumper rearwards bodily.
On my last one, I had to use a lever between the bumper and the body where the bottom of the rear lights are to get it started. Once started, it will come off "easily".